The present invention relates to a screen printing machine and, more particularly, to a machine that is able to screen print curved or cylindrical objects.
With reference to FIG. 7, a conventional machine for screen printing curved objects generally comprises a first pneumatic cylinder 10, a scraper means 20, a screen holder 30, and a second pneumatic cylinder 40. The first pneumatic cylinder 10 actuates the scraper means 20 to move. The scraper means 20 comprises a pair of scrapers which are drawn over a screen held by the screen holder 30. The second pneumatic cylinder 40 cooperates with a workpiece mold to secure a workpiece in place. The workpiece has a curved surface.
During operation, a screen held by the screen holder 30 is placed against a workpiece held by the workpiece mold and the second pneumatic cylinder 40. The scrapers of the scraper means 20 are drawn across the surface of the screen, pressing ink onto the workpiece.
A disadvantage of this conventional design is the low production capacity as only one workpiece per stroke can be screen printed. Another disadvantage is the low quality of the print as the workpiece does not rotate which limits the amount of curved surface which can be printed. Also, the conventional machine occupies a large amount of space for the work capacity it can accomplish.
Therefore, there exists a need in the field of screen printing machines for a machine which is able to print on the entire curved surface of a workpiece, which can screen print more than one workpiece at a time, and which does not occupy a relatively large amount of floor space.